Bench punch



' Dec. 13, 1932. c, SP'ENGLER 1,890,956

BENCH PUNCH Filed July 6, 1931 Patented Dec. 13, 1932 PATENT OFFICEHAROLD C. SPENGLER, OF ROCKFORD, ILLINOIS BENCH PUNCH Application fi eurui e, 1931. Serial No.548,973.

This invention relates to a new and improved bench punch for metalworking.

Bench punches are now mostly of the screw type and besides beingcomplicated and expensive in construction are subject to the objectionsthat they are slow in operation and cannot be used successfully in thepunching of oval or any other non-circular forms of holes because of thetendency for the punch to turn. It is therefore the principal object ofmy invention to provide a bench punch of the hand-lever type sodesignedas to secure the desired power without too massive construction, and toprovide a punch that is quicker in operation and adapted for thepunching of practically any shape of hole.

ther objects are:

1. To provide a bench punch incorporating a punch holder guided formovement in an over-arm and linked to the punch actuating lever in sucha way that the lever bears solid- 1y upon the punch holder in thepunching stroke, no load being imposed upon the pivot pins of the linkconnection other than that of simply retracting the punch holder on theupstroke of the aforesaid lever, whereby to permit the application ofconsiderable pressure on the punch without danger of any destructiveshearing action, and make for minimum wear;

2. To provide a bench punch having provision for the mounting ofdifferent sized bolster blocks on the anvil thereof according to thethickness of stock to be worked upon, the said blocks serving as dieholders.

The invention is illustrated in the accompanying drawing in which-Figure 1 is a side view of a bench punch made in accordance with myinvention, the same being shown closed; and

Fig. 2 is a cross-section on the broken line 22 of Figure 1.

The punch has the body thereof suitably cast in one piece so as toprovide a base 5 wlth pad portions 6 and 7 for fastening the same onto abench or other suitable support, the said base having an anvil 8 formedat the front end thereof and an over-arm 9 extending from the backthereof reaching over the anvil. Bolster blocks 10 of different sizesare arranged to be fastened onto the anvil 8 as by means of bolts 11entered through holes in the, flanges 12 provided on'opposite sides ofthe anvil. The anvil 8 is made hollow as ino dicated at 13 and providedwith a counterbore 14 in the top thereof to receive a pilot portion 15on the block 10 so as accurately to locate the block on the anvil andthus insure proper alignment between the die 16 and the I punch 17. Thedie 16 fits in a counterbore 18 i in the upper end of the bore 19provided in the block 10. Each block of a set going with the punchusually has the same shaped counterbore so that a'set of dies going withthe punch can be used with any block. The provision of a set of'thesebolster blocks makes it possible to set up the punch for a large varietyof jobs. An adjustablestop 20 is ordinarily provided in conjunction withthe bolster blocks and when once set facilitates the location of thestock so that a series of pieces can be punched alike with closeaccuracy and with an appreciable saving in time.

The punch 17 is suitably secured in a socket- 21 provided in a plungeror punch holder 22 or may be integral therewith. The plunger or punchholder has a close working fit in a guide hole 23 in the over-arm 9,whereby to guide the punch for movement in exact alignment with the dietherefor. The upper L end of the punch holder is slotted diametricallyin a fore and aft plane as indicated at 24: and has a link 25 fittingtherein and pivotally connected to the punch holder by means of a shortpin 26 fitting in registeringtransverse holes provided in the link andpunch holder. The pin is short enough to fit in the guide hole 23 inwhich the punch holder operates as previously stated. A punch ac- [mtuating lever 27 is pivoted at its rear end on top of the over-arm 9 atthe back thereof as indicated at 28 and extends forwardly to a pointover the punchholder 22 for an operating connection therewith. The lever27 has a slot 29 provided on the under side thereof at the front-endregistering with the slot 24 in the punch holder 22 and receives thelink25 therein. A pin 30 having a drive fit'in a transverse hole 31 providedin the leve'r'27 passes freely through a larger hole 32" provided in thelink 25 so as to complete the link connection between the lever 27 andthe punch holder 22 to take care of the raising of the punch holder bymeans of the lever through said link connection, and still provide forthe direct movement of the punch holder by the lever in the downstroke.In other words, the lever 27 can bear solidly on the upper end of thepunch holder 22 as clearly indicated at 33 on the down-stroke of thepunch, the link connection playing no part whatsoever in this operationbut being adapted merely to serve in the return or upstroke of the punchto raise the punch holder by means of the lever.

' This eliminates any danger of a destructive shearing action and makesfor long life, the wear being reduced to an absolute minnnum. Strippingjaws 34 are suitably secured as at 35 on opposite sides of the over-arm9 reaching down to a point just above the top of the work to facilitatethe withdrawal of the punch from the work in an obvious manner.

The punch, as will now appear, is designed for operation from in frontso that the work is in plain sight as the operator pulls down upon thehand lever 86 to operate the punch. The hand lever proper is preferablyin the form of a pipe threaded into a holder 37 provided on the end of ashort lever 36,

which facilitates matters in the shipment of the punch, the handle beingdetachable, and also permits insertion of as long or short a handle asthe operator desires. The lever 36 is pivoted on a bolt 38 between apair of side plates 39 which in turn are pivotally attached to theover-arm 9 by means of another bolt 40. Nuts 41 threaded on the ends ofthe bolt 38 and nuts 42 threaded on the ends of the bolts 40 hold theside plates in assembled relation to the lever and over-arm. A gearsegment 43 is formed on the end of the lever 36 on each side thereof andmeshes with a set of forwardly and upwardly inclined rack teeth 44-formed on the top of the lever 27 at each side thereof whereby to forcethe lever 27 downwardly. A cam surface 45 is formed on the bottom of thelever 27 which, like the sets of rack teeth 44, is forwardly andupwardly inclined. This cam surface has a roller 46 arranged to rollthereon, carried on a cross pin 47 mounted at its opposite ends on theside plates 39, whereby to raise the lever 27 by cam action as the lever36' is swung upwardly and rearwardly. The pin 47 is properly located sothat the cam surface 45 clears the roller 46 in the clownstroke of thepunch. It is only on the up stroke that the roller comes into play toforce the lever 27 upwardly by rolling on the cam surface 45.

I claim:

In a bench punch of the hand lever type, comprising a body portionformed to provide an anvil and an over-arm, a die mounted ment in a holein the over-arm to operate a punch in alignment with the die, a leverfor actuating the plunger pivotally mounted at one end on the bodyportion and having its other end disposed over the plunger and arrangedby direct engagement therewith to operate the same 011 the downstroke,the abutting ends of said lever and plunger being bifurcated, a linkconnection between the plunger and said lever in the bifurcated portionswhereby to permit nearly full length engagement of the plunger in thehole in said over-arm for guide purposes, and a hand lever mounted forswinging movement relative to the body portion and operatively connectedwith the aforesaid lever for positively operating the punch holder onthe downstroke by movement of the lever in one direction and on theupstroke by movement of the lever in the opposite direction, the linkconnection being constructed for a predetermined lost motion between thelever and plunger, whereby to insure positive engagement between theplunger and lever for downward movement of the plunger independently ofthe link connection, and where by the link connection serves to move theplunger upwardly on the return movement of the lever.

In witness of the foregoing I a'liix my signature.

HAROLD C. SPENGLER.

on the anvil, and a plunger guided for move-

